Found: YA Fiction - Girl thinks it's 19th century, searching for medicine

I think this book was published in the 1990s, if I remember correctly. It's about a girl whose family lives in a Williamsburg-like commune, but the children really think it's the 1800s. Since they haven't been vaccinated, they all end up sick (with smallpox or some similarly mostly eradicated disease) and this girl escapes into the real world to find someone to help them based on her mother's memory of the real world.

You then go on to learn that the person she calls for help is dead, and some guy is essentially robbing her. She finally calls a press conference and collapses on stage from fever.

Running Out of Time, I love that book!

(Also, it was the first time I had ever heard of Diphtheria - the sickness they hadn't been vaccinated against)

thanks so much!!!

I liked this book when I was young. I re-read later on and still found the book very enjoyable.

And the long awaited sequel just came out recently, Falling Out of Time.